How to read a timing slip (and why the 60-foot matters most)

After every pass, someone at the timing tower hands over a strip of paper about the size of a supermarket receipt. To a newcomer it looks like a lottery result. To a racer it is the most useful thing at the meeting: a record of exactly what the vehicle did, split into sections, down to the thousandth of a second.

This piece walks through a slip line by line. The example below is made up for illustration. It is not from any real run.

Mark	Left lane	Right lane
R/T	0.084	0.112
60 ft	1.021	1.065
330 ft	2.814	2.902
660 ft ET	4.210	4.334
660 ft MPH	158.40	154.12
1,000 ft	5.381	5.540
1/4 ET	6.395	6.588
1/4 MPH	197.61	192.30

How the timing works

The NZDRA's history describes the early days: races were started with a flag and timed with stopwatches, with a telephone line so a finish-line observer could tell the timer when to stop the watch. Today, light beams across the track detect each vehicle, and a computer works out the times for each section and the speeds at half track and the finish, to the millisecond.

The important idea is that there are beams at fixed distances down the track. Each time a vehicle breaks one, the computer notes the time. Each line on the slip is the time from the start to one of those beams.

Line by line

R/T, reaction time. How long the rider took to leave after the green light came on, measured at the start line. It is a measure of the rider's reflexes and timing, not the vehicle. A negative number means the rider left before the green: a red light, which in most racing loses the round on the spot.

60 ft. The time from the start line to a beam 60 feet (about 18 metres) down the track. This is where launch and traction show up. More on this below.

330 ft. The time to about 100 metres. By here the vehicle is well into its run and the clutch, in a bike that has one designed to slip, is doing much of its work.

660 ft ET and MPH. The eighth mile: half a quarter mile. Some tracks and classes race to here and finish. On a quarter-mile run, it is the half-track checkpoint, with a speed reading taken through a short trap around the mark.

1,000 ft. The distance the American nitro classes now race to. On a quarter-mile slip it is another checkpoint.

1/4 ET and MPH. The full quarter mile, 1,320 feet. The ET is the headline number. The speed, measured over a short distance before the finish line, tells you how hard the vehicle was still pulling at the end.

Slips are still usually printed in feet and miles per hour, even in New Zealand. Drag racing grew up in the United States and its measurements came with it.

Elapsed time is not the same as winning

This is the line that confuses newcomers most. The elapsed time clock for each lane only starts when that vehicle leaves the start line. Reaction time is measured separately. So the winner in a heads-up race is the one with the lowest reaction time plus elapsed time: the one who actually crossed the finish line first.

That means a slower vehicle can beat a quicker one if its rider reacts faster. Racers call this a holeshot win. It is one of the reasons drag racing is not as simple as "fastest bike wins".

In handicap or bracket racing, where each competitor nominates an expected time (a dial-in) and the slower one gets a head start, there is another twist. Going quicker than your dial-in, called breaking out, can lose you the round even if you crossed the line first. Not every class works this way; the NZDRA's history notes that the upper brackets remain heads up.

Why the 60-foot matters most

Look back at the example. The left lane was 0.044 seconds quicker to 60 feet. By the quarter mile it was 0.193 seconds quicker. The gap grew all the way down the track.

That pattern is typical. A vehicle that launches well is moving faster at the 60-foot beam, and it carries that extra speed into every section that follows. A vehicle that spins its tyre, lifts too far or bogs down at the start is playing catch-up for the rest of the run, and rarely makes it all back.

For bikes the 60-foot is especially revealing. A motorcycle has one driven tyre and a short, light chassis that wants to lift. The first metres are a balancing act between traction and wheelstand, controlled by the clutch, the tyre pressure, the chassis setup and the rider's body position. When a crew pulls a slip, the 60-foot time is usually the first number they look at, because it says most about whether the setup was right.

Reading a slip like a crew

Racers rarely look at a single slip on its own. They compare:

• Run to run. Did the changes made between rounds help? A better 60-foot but a worse 660-foot might mean the launch improved but something happened mid-track.
• Section by section. Subtracting one checkpoint from the next gives the time for each section. A section that is slower than expected points at where to look.
• ET against speed. A good speed with a poor ET often means a poor launch: the vehicle was strong at the end but lost time early. A poor speed with a reasonable ET can mean it ran out of steam or the rider shut off early.
• Against the weather. Air temperature, humidity and track temperature all change how a vehicle performs. Experienced crews note conditions next to every slip.

Where to see one

If you go to a meeting, the easiest way to understand slips is to ask a racer in the pits to show you theirs. Most are happy to, at least between rounds when they are not busy. Many tracks also put live times on a scoreboard at the finish line, showing ET and speed for each lane.

Our piece on your first drag meeting covers where to stand and what to bring. When you get there, look for the tower, the scoreboard and the queue of people waiting for their slips. Now you know what is printed on them.